1. Field of the Invention
The present invention relates to a multi-processing system and a multi-processing method. In particular, the invention relates to a multi-processing system and a multi-processing method, which can deal with an occurrence of a failure in a processor.
2. Description of Related Art
A multi-processing for executing processings in parallel by use of multiple processors secures high speed and safety level beyond an ability of a single processor. Thus, such multi-processing has attracted attentions in recent years. In particular, the multi-processing has gained attentions in that threads are assigned to multiple processors and executed thereby to carry out processings in parallel and enhance throughputs.
A multi-processor is significant for not only high-speed processing due to parallel processing but a high safety level in that when a failure occurs in one processor, the other processor not suffering a failure takes over the processing. However, a thread assigned to one processor may depend on a procedure or result of executing a thread assigned to the other processor. Hence, only through the re-execution of the thread assigned to the processor suffering from a failure by use of the other processor, the thread cannot necessarily be executed normally. To that end, various techniques for improving the processing speed and safety level of the multi-processing are being under study.
From the viewpoint of increasing the processing speed, there has been proposed a method of checking the number of operable processors and the number of memories for each cluster at the time of start-up for scheduling (see Japanese Unexamined Patent Publication No. 7-287064, for example). Further, from the viewpoint of enhancing the safety level, there has been proposed a method that can separate a processor suffering a failure without stopping a system (see Japanese Unexamined Patent Publication No. 10-247185).
However, the method disclosed in Japanese Unexamined Patent Publication No. 7-287064 cannot deal with the case where a failure occurs in a processor during a system operation. In addition, the method disclosed in Japanese Unexamined Patent Publication No. 10-247185 has a problem of poor workability because a user needs to start over from the beginning of the processing in case of failure.
As mentioned above, the conventional multi-processing system has a problem that it is impossible to deal with the case where a failure occurs in a processor during a system operation, or a problem of poor workability because a user needs to start over from the beginning of the processing in such a case.